How much pressure and temperature can a spaceship withstand?

Answer 1

Space Ships are designed the absolute cold of space, and they have reflection strips or coolers to survive the heat increase whenever the sun is visible.

As for air pressure, they typically use a pressure slightly less than that of the Earth at sea-level. They don't need to be high pressure containment vessels, only airtight ones. They use a lower pressure because your air supply has to be sent into orbit with you. Currently they use a Nitrogen/Oxygen mix, and have scrubbers to clean out the exhaled Carbon Dioxide. This was a major problem on Apollo 13. Apollo one was the first disaster where astronauts where killed. There was a fire in their cabin, in a pure oxygen environment. When the technicians tried to rescue them the lower air pressure in the command module defeated them, since the hatch opened outward and the surrounding air pressure was higher. This is why most hatches are designed to either open in or to have equivalent air pressure on both sides to make it easier to open them. Only craft that voyage underwater need hulls that can withstand a higher external pressure. The Space Shuttle uses quartz windows, normal glass would be strong enough but it wouldn't survive re-entry. When the engineers were looking for a way to lighten the Shuttle they shaved the quartz windows (in space travel even ounces count).

In fact the most dangerous part of space travel is the re-entry and the craft has to be designed to handle it. The capsules like Apollo and Mercury used heat shields, some of which would be meant to burn off during re-entry (to remove the heat). The space shuttle uses expensive clay tiles created with exotic materials and rare earths so they can survive. The next program Orion will go back to using capsules and heat shields.

Answer 2

The temperature is reduced by putting it into the rotisserie mode when on long trips. That balances the hot and cold .